Question: Simplify the following expression: $k = \dfrac{30xz + 30z^2}{40xz} + \dfrac{30z^2}{40xz}$ You can assume $x,y,z \neq 0$.
Explanation: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{30xz + 30z^2 + 30z^2}{40xz}$ $k = \dfrac{30xz + 60z^2}{40xz}$ The numerator and denominator have a common factor of $10z$, so we can simplify $k = \dfrac{3x + 6z}{4x}$